


Keep Your Bed Warm

by verucasalt123



Category: Teen Wolf (TV)
Genre: Anal Fingering, Anal Sex, Birthday, Cuddling & Snuggling, Established Relationship, Father-Son Relationship, Friendship, Humor, Kissing, M/M, Sheriff Stilinski Knows, Top Derek
Language: English
Status: Completed
Published: 2014-03-07
Updated: 2014-03-07
Packaged: 2018-01-14 21:29:26
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,865
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1279543
Author URL: https://archiveofourown.org/users/verucasalt123/pseuds/verucasalt123
Summary: <blockquote class="userstuff">
              <p>Stiles celebrates turning eighteen with his friends and his dad and his boyfriend.</p>
            </blockquote>





	Keep Your Bed Warm

**Author's Note:**

> I never thought I’d write the “Stiles and Derek have sex on Stiles’ 18th birthday” fic. But birthday was this week’s prompt, and I haven’t written any porn in forever, so I did it anyway. Title stolen from Sufjan Stevens’ “Happy Birthday”.
> 
> This is tagged for underage because there is sexual activity before Stiles turns 18, but the actual sex occurs when Stiles is 18.

Waiting around for your birthday when it’s close is a pretty exciting time when you’re a little kid; Stiles remembered it well. Wondering what kind of presents he’d get, how many people would call, how much cooler his cake would be than Scott’s had been the year before. Claudia was a traditionalist, and despite her very busy full time job, there was _never_ store-bought cake pre-decorated at the Safeway bakery on any special occasion in the Stilinski household.

This year, though, the anticipation was so much more intense. There were no thoughts of desserts or presents or parties; they were all too old for silly games and rented clowns. Friends sometimes exchanged gifts or just birthday wishes, parents handed over cash (which was really the only thing most teenagers wanted anyway) and Stiles was practically counting down the hours. 

High school graduation was closing in fast. After the Sheriff found out about the supernatural element of life in Beacon Hills, he was slightly less disapproving when Stiles started dating Derek. It was clear Derek cared greatly for Stiles and the Sheriff knew his son was in good hands with someone who would protect Stiles with his life. 

Sties may have gotten away with bending and breaking rules plenty of times in the past, but when the subject at hand was _sex with Derek Hale_ , they weren’t talking rules, they were talking about a real live actual law. Even though it would reflect badly on him professionally, the Sheriff hadn’t ever really thought his son would remain a virgin until he turned eighteen. The number was arbitrary, a higher age of consent than most states, and to be completely honest Stiles was more than capable of making his own decisions regarding consent issues. It was his fatherly duty, however, to embarrass his son by making a production about how Stiles and Derek having sex would be illegal. 

Not that it was actually necessary. Because Derek was pretty damn serious about waiting until Stiles was eighteen. It frustrated Stiles to no end, and it wasn’t easy for Derek either, but he wouldn’t budge. Stiles doubted Derek was worried about getting locked up; his guess (not that he would ever in a million years say it out loud) was that Derek might have some kind of hang-up left over from the days when he’d engaged in a sexual relationship with an adult while he was still a teenager. 

Making things a little easier was the fact that both Derek and Stiles were quite creative and always found ways to pleasure each other without going that little extra step that would technically count as Stiles’ loss of virginity. Derek’s number one rule was that neither of them would _penetrate_ the other, but just about everything else was on the table. So it wasn’t like they were making out and going home with blue balls for months. 

When Stiles voiced his concern about being ‘ready’ for sex (physically, because in all other ways he was so fucking ready, like wicked ready, willing, able, desperate…), Derek still wouldn’t finger him. Instead, he coached Stiles on fingering himself. It had been slow going at first, the sensation so strange and foreign to Stiles, and it took forever to find a decent angle to make it feel good. It was definitely worth it seeing how patient and concerned Derek was, even treating Stiles to a real live demonstration before he ever even tried it himself. Derek had coated his fingers with the old standby unscented clear Astroglide (no way he could tolerate the types of lube with chemical smells and tastes added in) and gotten on his knees in the middle of his bed, Stiles sitting close by _for educational purposes_ as Derek somehow managed to string together coherent sentences so he could try to show Stiles the basics. 

_I think it’s easiest and feels best like this, but it can be nice when you’re on your back, too. Just tougher to get the angle right if you’re not experienced._

_You gotta warm up the lube first, see, how I’m… you just kind of rub your fingers together. That way there’s not this shock of something cold on your asshole._

_Probably you’ll wanna start how I am, just kind of rubbing around it, don’t just jam one of your fingers in right away, try to get used to the feeling first._

Mesmerized, Stiles just sat slack-jawed and wide-eyed as he watched Derek reach behind himself and gently spread the lube around his hole, rubbing a finger against and around it before he finally eased one inside just a little bit at a time. Once Derek’s had one finger inside himself, he moved it slowly in and out, explaining to Stiles that when he did this, he’d be able to feel the muscles relaxing around the intrusion. He even warned him that at first it probably wasn’t going to feel good at all, just kind of weird and very likely painful for at least a little while, but that it would get better and eventually be pretty fantastic. 

Really, Stiles had no reason to doubt Derek’s words as he heard the soft moans and drawn-out _ahhhhhh_ sounds that had started escaping Derek once he had added another finger and was pushing in as well as pushing back against it. 

_It’ll take time and practice, but you can find your prostate like this and I can promise you that will change everything. You just have to kind of crook your fingers a bit, feel around for it, but it’s so worth it when it happens._

And it must have happened just then for Derek, because Stiles heard a sharp intake of breath as Derek cursed (which, what even was his life, turned Stiles on almost as much as the live action porn six inches from his face, because Derek _never_ cursed and it sounded incredibly hot) and his torso dropped a little closer to the mattress. Stiles had spent a lot of time masturbating during his teen years, but hadn’t ever experimented with anything like this, though he’d thought about it. Now he regretted not having done it sooner as he saw how Derek enjoyed it so much. He wanted to ask if Derek had been with other guys before or if he’d only done this on his own, but that would be a question for later. For now, he just enjoyed the show until Derek, red-faced and still hard as a rock, pulled out his fingers as if getting himself off was completely irrelevant and asked Stiles if he was ready to give it a try himself. 

The answer to that question was obviously a resounding ‘yes’, and Stiles thought it was pretty damn good for his first time. Derek had been right, at first it was just really fucking strange and honestly kind of made him feel like he had to use the bathroom. When he said as much, Derek chuckled and admitted that he probably should have mentioned that sensation as well. Trying to keep the mood light, Stiles told Derek to make a note so he could add it to the PowerPoint slideshow he ought to create so he could share his knowledge with the world. (Not that he meant a word of it, because Stiles didn’t want Derek sharing his knowledge or anything else of his with anyone, at all, under any circumstances.)

They ended up getting each other off and just added fingering themselves to the rest of their _technically not actually having sex_ activities for the next few weeks. It added another really exciting dimension to all the fantastic things they already did together and made Stiles even more impatient because now that he’d seen Derek stimulating himself that way he was even more anxious to have those fingers, and then Derek’s dick, inside of him. 

Stiles was lucky this year, too, having his birthday fall on a Saturday. As per tradition, Scott hurled himself into Stiles’ room and jumped on his bed to wake him up at the crack of eleven in the morning (much better than when his birthday was on a weekday and Scott pounced on him at seven a.m. so he could be the first to sing him the ‘you look like a monkey and you smell like one too’ version of the birthday song), then his dad took them both to lunch at the place with the eggplant parmesan that Stiles had always sworn must have some kind of illegal drugs in the sauce. Lydia knew they would be there and popped in for long enough to kiss all three of them on the cheek and hand Stiles the brightest, pinkest, glittery-est card in the Hallmark store with a little note written inside that said _have fun getting laid tonight xoxoxoxo_ in her perfect flowery script. He tried to scowl at her, but that was a tough look to pull off while he was blushing so hard, so he just rolled his eyes and refused to show it to his lunch companions. 

The previous evening, when Stiles brought up to his dad that he’d be going out with Derek the next night to celebrate, the Sheriff had just scrubbed a hand across his resigned face and told Stiles he expected him home, _accompanied by Derek_ , for dinner on Sunday. Hell, his boy had actually waited to have sex until he turned eighteen, and had been completely honest about the fact that he was planning on that wait being over on his actual eighteenth birthday – he figured the kid deserved a nice night with no worries about a curfew or anything else. He’d seen plenty of kids ending their celebration at the jail, or worse, the hospital, after drinking or partying too much. Sure, there was going to be sex, but that was bound to happen eventually and at least he’d know Stiles was in a safe place with someone who would take care of his son and seemed like he might even love him a little bit. 

When Stiles finally got a minute alone to call Derek and tell him he was allowed to spend the night, they were both thrilled. Derek hadn’t voiced any objections to Stiles keeping his usual birthday traditions with his dad and his best friend for the day, because he knew that the night was his. 

Turning eighteen was like winning the lottery for Stiles. The past couple of years hadn’t been easy ones; he and all of his friends had been through the wringer many times over. It was hard to imagine there would be a night like this in store for him – Derek cooking him dinner, presenting him with a graphic tee ordered online that had the most ridiculous logo on it (read: ridiculous to Derek, hysterical to Stiles), the two of them making out on the couch before making their way to the bed. 

They’d taken each other’s clothes off plenty of times before, but it seemed different tonight because of where they knew things were headed. Derek thought losing your virginity was a big deal; Stiles thought virginity was a meaningless social construct; Derek totally called him on quoting that directly from Lydia. Still kissing and touching each other all over, Stiles couldn’t stop himself from scooting down the bed and taking Derek’s half-hard cock in his mouth, licking and sucking until it was fully erect and Derek was starting to sweat. It didn’t take much strength for Derek to maneuver Stiles onto his back as he pulled the lube out of the drawer in the nightstand and smiled. Stiles stopped him with a look before he could get the requisite _are you sure, are you ready, is this okay_ questions started. Stiles was far past ready to have Derek inside him, and he turned down the suggestion that it might hurt less if he was on his hands and knees. He wanted to be able to see Derek while he opened him up for the very first time, for Derek to be able to see him too. 

Without prompting, Stiles bent his knees and spread his legs to give Derek access while Derek coated his fingers with lube. Using one hand to softly stroke the outside of Stiles’ thigh, he pressed gently around Stiles’ hole, getting it wet and helping him relax before finally _finally_ pushing his middle finger slowly into him. Derek’s delight was obvious at feeling the tight heat waiting for him there and it didn’t take long before Stiles was asking for more. They kept the pace leisurely but not teasingly slow. Both of them wanted to enjoy every moment of this experience. When Stiles felt the pads of Derek’s fingers brush across his prostate, he shouted and nearly shot off the bed. Derek just added a smile to the intense look on his face and aimed to hit that spot again as he added another finger. 

And sure, it did hurt a little, Derek’s fingers were thicker than Stiles’ own, but the little bit of hurt was forgotten quickly because Derek was making him feel so damn good. His cock was harder than he could ever remember and leaking so much precome. He groaned when Derek used his free hand to collect all he could from Stiles’ slit and lick it off. At that point, Stiles was a little concerned about premature ejaculation and urged Derek to please just fuck him already. 

They’d had the condom discussion, which pretty much boiled down to Derek acknowledging that neither of them had any sexually transmitted diseases to share with each other and Stiles insisting that easy clean-up was going to be the last thing on his mind. So Derek eased Stiles’ knees back a little more, slicked up his cock with lube and very carefully started to guide the head into Stiles’ ass. And that – well, okay, Stiles was breathing hard and holding onto Derek’s shoulders for dear life because it _hurt_ , the stretch and the burn of a dick inside of him was much more than being fingered. Derek went slowly, though, pushing in just a little at a time, letting Stiles take deep breaths and adjust around him. By the time Derek was all the way inside, Stiles could still feel the soreness but being filled up like that was amazing. After just a few moments, Derek started to move, thrusting shallowly and rolling his hips against Stiles. Once Stiles started meeting all of Derek’s moves and pushing back against him, Derek pulled out a little more each time before thrusting back in until he was pulling almost all the way out and quickly filling Stiles up again. 

By that time, the pain was all but forgotten on Stiles’ part, all he could feel was satisfaction, the drag of Derek’s cock along the inside of him, the jolts of excitement when Derek hit his prostate. He was getting pretty close to coming just from the friction of his dick between their bodies. It was clear that Derek was getting close, too, as he whispered encouragements and sweet words into Stiles’ ear and sweat dripped from his hairline down the side of his face. When he knew he couldn’t hold off any longer, Stiles swore and went still all over as he shot his load between them. Derek pushed inside of him just a few more times, a little harder with Stiles so pliant in his post-orgasmic haze, before he growled and let himself go, filling Stiles up with his release. 

It took a few minutes before either of them spoke after Derek slid out and rolled them onto their sides with his arms around Stiles. Though he wasn’t usually the one to break the silence, Derek said, “I hope that lived up to your expectations for your first time.”

Stiles responded, “That exceeded every expectation I’ve ever had about sex, babe. I’m not kidding.”

“Happy birthday”, Derek said, kissing Stiles’ neck. 

“You have to have dinner with my dad tomorrow, Derek. You have to sit across the table from him and know that he knows you fucked me tonight.”

“I’ll always be able to count on you to ruin a perfectly good afterglow, won’t I?”

Stiles laughed. “Yep. Pretty much.” He was quiet again for another minute but then turned around to look at Derek and asked, “Is this a bad time or a good time for me to tell you that I love you?”

Derek’s face lit up and he said, “Stiles, there’s never going to be a bad time for you to tell me that.”

“So you love me too, huh? I knew it!”

“It’s not like I was trying to keep it a secret, you know.”

“Sure, but you didn’t say it. Hey, you _still_ haven’t said it!”

“I love you, Stiles. I love you, and I love what we have together, and I even love having dinner with your dad after you’ve given up your meaningless social construct of a virginity to me.”

“That’s more like it. I’m gonna turn back over now. It’s my birthday and I get to be the little spoon.”


End file.
